Lock-guard.



T. J. MODONNELL. ILOGKGUARD. APPLICATION nun 1-23.13, 1911.

1,001,157. Patented Aug. 22,1911.

COLUMBIA PLANOGRAPH 20.. WASHINGTON u c THOMAS J. MCDONNELL, 0F SEATTLE, WASHINGTON.

LOCK-GUARD.

Application filed. February 13, 1911.

Specification of Letters Patent.

Patented Aug. 22, 1911.

Serial No. 608,452.

To all whom ttma'y concern:

Be it known that I, THOMAS J. MCDON- NELL, a citizen of the United States of America, and a resident of the city of Seattle, in the county of King and State of Vashington, have invented certain new and useful Improvements in Lock-Guards, of which the following is a specification.

My invention relates to locks, having more particular reference to guards for the key holes thereof, and has for its primary object the provision of a device of this type which will block or prevent the insertion of a key or other instrument from one side of the lock.

A further object resides in a novel provision of this character which can be combined in the lock structure to be under control of the operating key thereof.

With the above and other objects in View to be referred to as my description progresses, my invention resides in the structural features, arrangements and combinations of parts hereinafter described and succintly defined in my appended claims.

Referring to the accompanying drawing, illustrating a preferred embodiment of my invention, and wherein like numerals of reference indicate like parts throughout the several views: Figure 1 is a side elevation of a lock with my guard in its inactive position, a portion of the lock casing being broken away. Fig. 2 is a fragmentary view thereof, on enlarged scale, with one side wall of the casing removed. Fig. 3 is a section taken on line 3 of Fig. 1, and Fig. 4: is a perspective of the guard and the locking device therefor, the latter being shown fragmentarily and illustrated as having been moved upwardly to release the guard.

I have shown my guard 1 in connection with a lock, of a well known type, comprising a casing 2 having a. removable side wall 2 normally secured in position by a screw 3.

Reference numeral 4 indicates the lock bolt and 5 the tumbler therefor arranged to be lifted through the medium of a key in serted through the key holes 6, 7, from either side of the lock.

Guard 1 conveniently comprises a slide, having an angular edge extension 1 engaged in a cut out 2 of an inwardly proj ecting flange 2", of wall 2, to be thereby firmly held while being free for sliding across the key hole 6.

holes 6, 7 by which construction the guard normally projects on opposite sides of key hole 6 and can thereby be held for a more perfect sliding movement which is effected through engagement of key 8 with one or the other of two engaging parts 11, 12, consisting of pins provided on the inner face of guard 1 in suitably spaced relation to be alternately engaged by a shoulder 8 of the key bit 8*.

With the guard 1 arranged in normal or inactive position, adjustment thereof is effected by inserting key 8 through key hole 7 until shoulder 13 of the key stem abuts .the adjacent wall of the casing 2. The key is now turned in the usual manner to bring its bit 8 into engagement with surface 9 of tumbler 5 to thereby lift the latter prior to throwing bolt 1. As tumbler 5 releases guard 1, through withdrawal of teeth 9 from teeth 1 shoulder 8 of bit 8 engages pin 11 and through such engagement slides guard l a suflicient distance to block key hole 6, as indicated by broken lines in Fig. 2, during which movement the projecting inner end portion of the bit pin is received in a groove 10 of the guard. This adjustment is completed as shoulder 8 wipes from pin 11, and bit 8 then wipes from tumbler surface 9, thereby freeing tumbler 5 to again lock guard l, and permitting of the removal of the key from the lock, if this be desired.

In withdrawing bolt 4, shoulder 8 engages pin 12 and thereby shifts guard 1 back to normal position, as will be readily understood.

The invention is particularly adapted for guarding the lock from operation or tampering from the outside, and consequently the lock would be arranged with its key opening 6 facing the outside, but I have made provision for the proper operation of the look from the outer side of the door, this consisting in providing the opening 10 in the guard, and forming bit 8 With a cut-out 8 which will freely receive pins 11 and 12 and thereby enable the bit to clear the latter When key 8 is inserted through key hole 6 and through key hole 10 of guard 1, at Which time the guard obviously must be in its inactive position.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent of the United States of America, 1s:

1. In a look, a casing provided in its opposite side vvalls with key holes, a guard slidably supported in said casing for movement across one of the key holes thereof, the side Wall provided With the other of said key holes being removable, an inwardly projectlng means on the last named side Wall of said casing engaged with said guard for guiding the same in its movement, and key engaging means on said guard arranged in the path of a key inserted through the key hole in said removable Wall of the casing.

2. In a lock, a casing provided in its opposite side Walls With key holes, a guard in said casing for covering one of the key holes thereof, said guard having an outwardly projecting flange, the side Wall having the other of said key holes being removable and provided With inwardly projecting means receiving the flange of said guard to thereby guide the latter in its movement, and key engaging means on said guard arranged in the path of a key inserted through the key hole in said removable Wall of the casing. Signed at Seattle, WVashington this 4th day of February 1911.

THOMAS J. MQDONNELL.

lVitnesses:

S'HEPHEN A. BROOKS, ARLITA ADAMS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

